ANS:C - Re^0.8, Re^0.5

The Nusselt number (Nu) is a dimensionless number used in fluid dynamics and heat transfer to characterize the convective heat transfer coefficient. The relationship between the Nusselt number and the Reynolds number (Re) varies depending on whether the flow is laminar or turbulent. In laminar flow, the relationship between the Nusselt number and the Reynolds number is typically expressed as: Nu∝Re13Nu∝Re31​ In turbulent flow, the relationship between the Nusselt number and the Reynolds number is typically expressed as: Nu∝Re0.83Nu∝Re30.8​ So, in turbulent flow, the relationship is closer to Re0.27Re0.27, and in laminar flow, it is closer to Re0.33Re0.33. Therefore, the correct option is: Re^0.8, Re^0.33.